All of the professional fotogs I know are paid not for photos the have taken, but for photos people would like them to take. The photos that they have taken are just proof that if you hire them to take photos for you, they will be good.
In this way, I think this author's point of view is slightly more economically advantageous than the "this photo cost $6500" guy.
I know one who does both. She is actually quite good but probably makes only a single digit percent of her income on stock. Mostly her portfolio serves as a starting point where clients say, "like this one only of my subject".
The stock photo industry is getting bigger, while profit-per-photo is plummeting. There are still a number of well-known photogs in this space, some of whom are doing remarkably well for themselves.
My impression of that industry is that it's all about process - to make a living doing it you need to have an extremely streamlined process and churn out a vast amount of work.
In this way, I think this author's point of view is slightly more economically advantageous than the "this photo cost $6500" guy.